Along with the miniaturization of various electronic devices, designs of electronic components correspondingly follow the miniaturization trend. FIG. 1 shows a switch element that controls an output signal. Referring to FIG. 1, a conventional switch element includes a switch housing, a common pin 1, an normally closed pin 2 and an normally open pin 3. The switch housing includes an accommodating space, an elastic plate 41 disposed in the accommodating space, and a support rack 42. The support rack 42 has a movement track 421 for the elastic plate 41 to move therein, and an insulation block 422 disposed in the movement track 421. The common pin 1 penetrates through the switch housing to extend into the accommodating space 41 to become electrically in contact with the elastic plate 41. The normally closed pin 2 is partially embedded in the support rack 42, and extends into the movement track 421 to abut against one side of the simulation block 421. The normally open pin 3 penetrates through the switch housing and is exposed in the movement track 421, with an exposed part abutting against the opposite side to the side abutted against by the normally closed pin 2. When the elastic plate 41 is pressed by an external force and thus moves in the movement track 421, the elastic plate 41, from the normally closed pin 2 originally in contact with, crosses the insulation block 422 to become in contact with the normally open pin 3.
As the conductive elastic plate 41 comes into contact with the normally closed pin 2 or the normally open pin 3 during up-and-down movements, a contact point is melted by an electric arc as a result of electric discharge. Thus, carbon residue is generated and scattered to the surroundings and even deposited on the insulation block 422. With long-term accumulation, the carbon residue forms a conductive layer that connects the normally closed pin 2 to the normally open pin 3. During a high-voltage test, the conductive layer electrically connects the normally closed pin 2 to the normally open pin 3 in a way that, the micro-switch not only becomes malfunctioning but also fails safety certification of higher amperage and an expected product yield rate.